Aspects of the disclosure relate to networked computing technologies and location services. In particular, aspects of the disclosure relate to systems, methods, apparatus, and computer readable media for providing network based and network assisted positioning services to a mobile electronic device.
The Secure User Plane Location (SUPL) solution is a user plane location solution defined by the Open Mobile Alliance (OMA) that uses internet protocol technology to support location based services related to mobile devices. One focus of the SUPL solution is providing assistance data (AD) to a mobile device whose location is needed (e.g. by an application on the mobile device or by the user of the mobile device) to assist the mobile device to make suitable location related measurements and, in some cases, to compute its location using such measurements. While there are a variety of ways to provide location assistance data to a mobile device, SUPL provides a standardized environment with a simple client server model together with standardized protocols defining interaction between a SUPL location server, known as a SUPL Location Platform (SLP) and a mobile device, known as a SUPL Enabled Terminal (SET). The SUPL solution also supports the conveyance of a location estimate from a SET to an SLP, the conveyance of location related measurements from a SET to an SLP when the SLP rather than SET will compute the SET's location and the exchange of positioning and SUPL capabilities between a SET and an SLP. SUPL can, in addition, support various service related features that enhance simple positioning such as obtaining SET location estimates on a triggered or periodic basis and obtaining historic SET locations. The various capabilities supported by SUPL may significantly improve location support for mobile devices and may enable more accurate and reliable location of a mobile device in comparison to methods that rely on simple standalone positioning support in a mobile device based on measurements of, for example, the US Global Positioning System (GPS).
In devices that make use of SUPL services, the standard implementation involves a mobile device being assigned a fixed single home SLP (H-SLP) based on a pre-provisioned setting with the H-SLP being associated with either a home operator for the mobile device or some other preferred provider of location services. A device uses the pre-provisioned setting, which is the H-SLP address, to establish a connection with the device's single H-SLP when engaging in a SUPL location session. Information about additional local devices (e.g. wireless base stations and WiFi access points (APs) whose signals can be received by the device and used to help determine the device's current location) may then be accessed via the H-SLP. SUPL also defines more local SLPs, known as Discovered SLPs (D-SLPs) that may in some scenarios provide more extensive and appropriate information (e.g. better assistance data) to a device than its H-SLP. For example, when a device is roaming in a distant location from its H-SLP or is at a location (e.g. inside a building or at a venue for which its H-SLP has little or no information), a D-SLP nearby to the device (e.g. associated with the same building or venue within which the mobile device may be located) may be able to provide assistance data containing information for more base stations and access points local to the device than the device's H-SLP. This additional information may enable improved location support based on the device acquiring and measuring signals from these additional base stations and access points. An ability to discover and make use of suitable D-SLPs may therefore be an advantage to mobile devices and their users.